Anchoring units for leads of implantable electric stimulation systems and methods of making and using

ABSTRACT

A nerve stimulation lead has a distal end, a proximal end, and a longitudinal length. The nerve stimulation lead includes a plurality of electrodes disposed at the distal end, a plurality of terminals disposed at the proximal end, and a plurality of conductive wires electrically coupling the plurality of electrodes electrically to the plurality of terminals. The nerve stimulation lead also includes at least one anchoring unit disposed on the nerve stimulation lead. The at least one anchoring unit is configured and arranged for anchoring the nerve stimulation lead against a bony structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 12/413,081 filed on Mar. 27, 2009, which claimed the benefit ofU.S. Provisional Patent Application No. 61/041,536 filed on Apr. 1,2008, all of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention is directed to the area of implantable electricalstimulation systems and methods of making and using the systems. Thepresent invention is also directed to implantable electrical stimulationsystems having leads with one or more anchoring units coupled to theleads for anchoring the leads on or around foramina of bony structures,as well as methods of making and using the anchoring units, leads, andimplantable electrical stimulation systems.

BACKGROUND

Implantable electrical stimulation systems have proven therapeutic in avariety of diseases and disorders. For example, spinal cord stimulationsystems have been used as a therapeutic modality for the treatment ofchronic pain syndromes. Deep brain stimulation has also been useful fortreating refractory chronic pain syndromes and has been applied to treatmovement disorders and epilepsy. Peripheral nerve stimulation has beenused to treat chronic pain syndrome and incontinence, with a number ofother applications under investigation. Functional electricalstimulation systems have been applied to restore some functionality toparalyzed extremities in spinal cord injury patients. Moreover,electrical stimulation systems can be implanted subcutaneously tostimulate subcutaneous tissue including subcutaneous nerves such as theoccipital nerve.

Stimulators have been developed to provide therapy for a variety oftreatments. A stimulator can include a control module (with a pulsegenerator), one or more leads, and an array of stimulator electrodes oneach lead. The stimulator electrodes are in contact with or near thenerves, muscles, or other tissue to be stimulated. The pulse generatorin the control module generates electrical pulses that are delivered bythe electrodes to body tissue.

BRIEF SUMMARY

In one embodiment, a nerve stimulation lead has a distal end, a proximalend, and a longitudinal length. The nerve stimulation lead includes aplurality of electrodes disposed at the distal end, a plurality ofterminals disposed at the proximal end, and a plurality of conductivewires electrically coupling the plurality of electrodes electrically tothe plurality of terminals. The nerve stimulation lead further includesat least one anchoring unit disposed on the nerve stimulation lead. Theat least one anchoring unit is configured and arranged for anchoring thenerve stimulation lead against a bony structure.

In another embodiment, a lead assembly includes a nerve stimulation leadand a spring configured and arranged to anchor the nerve stimulationlead during implantation of the nerve stimulation lead. The nervestimulation lead has a distal end, a proximal end, and a longitudinallength. The nerve stimulation lead includes a plurality of electrodesdisposed at the distal end, a plurality of terminals disposed at theproximal end, and a plurality of conductive wires electrically couplingthe plurality of electrodes electrically to the plurality of terminals.The spring is disposed around at least a portion of the nervestimulation lead.

In yet another embodiment, a nerve stimulation lead has a distal end, aproximal end, and a longitudinal length. The nerve stimulation leadincludes a plurality of electrodes disposed at the distal end, aplurality of terminals disposed at the proximal end, and a plurality ofconductive wires electrically coupling the plurality of electrodeselectrically to the plurality of terminals. The nerve stimulation leadalso includes a plurality of tines configured and arrangedcircumferentially around the nerve stimulation lead. Each tine has anundeployed position in which it lies against the lead and a deployedposition in which it projects outward from the lead. The plurality oftines are configured and arranged to change from the undeployed positionto the deployed position by rotating at least a portion of the nervestimulation lead after the nerve stimulation lead has been implanted ina body of a patient.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following drawings. In the drawings,like reference numerals refer to like parts throughout the variousfigures unless otherwise specified.

For a better understanding of the present invention, reference will bemade to the following Detailed Description, which is to be read inassociation with the accompanying drawings, wherein:

FIG. 1 is a schematic view of one embodiment of an electricalstimulation system, according to the invention;

FIG. 2A is a schematic view of one embodiment of a proximal portion of alead and a control module of an electrical stimulation system, accordingto the invention;

FIG. 2B is a schematic view of one embodiment of a proximal portion of alead and a lead extension of an electrical stimulation system, accordingto the invention;

FIG. 3 is a schematic front view of one embodiment of a sacrum thatincludes foramina through which sacral nerves may extend, according tothe invention;

FIG. 4A is a schematic side view of one embodiment of a distal portionof a lead with tines disposed in an undeployed position on the leaddistal to a plurality of electrodes, according to the invention;

FIG. 4B is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 4A with tines disposed in a deployed positionon the lead distal to a plurality of electrodes, according to theinvention;

FIG. 4C is schematic side view of one embodiment of a distal portion ofthe lead shown in FIG. 4A extending through a foramen of a sacrum, thelead having tines disposed on the lead distal to a plurality ofelectrodes, the lead also having a portion of a sleeve disposed over thetines to maintain the tines in an undeployed position, according to theinvention;

FIG. 4D is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 4C extending through a foramen of a sacrum andanchored to the sacrum by tines disposed in deployed positions at thedistal portion of the lead, according to the invention;

FIG. 5A is a schematic side view of one embodiment of a distal portionof a lead with tines in deployed positions disposed between each of aplurality of electrodes, according to the invention;

FIG. 5B is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 5A with tines in deployed positions disposedbetween some of a plurality of electrodes, according to the invention;

FIG. 5C is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 5B anchored to the walls of a foramen of asacrum by tines disposed in deployed positions between some electrodesat the distal portion of the lead, according to the invention;

FIG. 6A is a schematic axial cross-sectional view of one embodiment of alead that includes a plurality of tines spirally arranged in undeployedpositions in an annular groove disposed on the lead, according to theinvention;

FIG. 6B is a schematic axial cross-sectional view of one embodiment ofthe lead shown in FIG. 6A with a plurality of tines spirally arranged inpartially deployed positions in an annular groove disposed on the lead,according to the invention;

FIG. 6C is a schematic axial cross-sectional view of one embodiment ofthe lead shown in FIG. 6A with a plurality of tines spirally arranged infully deployed positions in an annular groove disposed on the lead,according to the invention;

FIG. 6D is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 6A anchored to the walls of a foramen of asacrum by a plurality of tines spirally arranged in fully deployedpositions in an annular groove disposed at the distal portion of thelead between two electrodes, according to the invention;

FIG. 6E is a schematic perspective view of one embodiment of a portionof the lead shown in FIG. 6A, the lead including cutouts disposed in anouter ring, according to the invention;

FIG. 6F is a schematic perspective view of one embodiment of a portionof the lead shown in FIG. 6A, the lead including a tine partiallyadvanced from each of a plurality of cutouts disposed in an outer ring,according to the invention;

FIG. 7A is a schematic axial cross-sectional view of one embodiment of alead with a spring disposed in an undeployed position in an annulargroove disposed on the lead, according to the invention;

FIG. 7B is a schematic axial cross-sectional view of one embodiment ofthe lead shown in FIG. 7A with a spring disposed in a deployed positionin an annular groove disposed on the lead, according to the invention;

FIG. 7C is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 7A extending through a foramen of a sacrum andanchored to the sacrum by a spring disposed in a deployed position onthe lead distal to a plurality of electrodes, according to theinvention;

FIG. 7D is a schematic perspective view of one embodiment of a portionof the lead shown in FIG. 7A, the lead including a cutout disposed in anouter ring, according to the invention;

FIG. 7E is a schematic perspective view of one embodiment of a portionof the lead shown in FIG. 7A, the lead including a spring partiallyadvanced from a cutout disposed in an outer ring, according to theinvention;

FIG. 8A is a schematic side view of one embodiment of a distal portionof a lead with a stent disposed in an undeployed position over a portionof the lead distal to a plurality of electrodes, according to theinvention;

FIG. 8B is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 8A with a stent disposed in a deployedposition over a portion of the lead distal to a plurality of electrodes,according to the invention;

FIG. 8C is a schematic side view of another embodiment of a distalportion of the lead shown in FIG. 8A with a stent disposed in a deployedposition over a portion of the lead distal to a plurality of electrodes,according to the invention;

FIG. 8D is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 8A extending through a foramen of a sacrum andanchored to the sacrum by a stent disposed in a deployed position over aportion of the lead distal to a plurality of electrodes, according tothe invention;

FIG. 9A is a schematic side view of one embodiment of a distal portionof a lead with an expandable sphere disposed in an undeployed positionon the lead distal to a plurality of electrodes, according to theinvention;

FIG. 9B is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 9A with an expandable sphere disposed in adeployed position on the lead distal to a plurality of electrodes,according to the invention;

FIG. 9C is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 9A extending through a foramen of a sacrum andanchored to the sacrum by an expandable sphere disposed in a deployedposition on the lead distal to a plurality of electrodes, according tothe invention;

FIG. 10A is a schematic side view of one embodiment of a distal portionof a lead with a section of deformable material disposed in anundeployed position on the lead distal to a plurality of electrodes,according to the invention;

FIG. 10B is a schematic longitudinal cross-sectional view of oneembodiment of the lead shown in FIG. 10A, the lead including an innersection that may be used to compress deformable material between adistal tip and an outer section of the lead, according to the invention;

FIG. 10C is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 10A with a section of deformable materialdisposed on the lead distal to a plurality of electrodes and with aportion of the lead distal to the deformable material longitudinallycompressed to radially expand the deformable material into a deployedposition, according to the invention;

FIG. 10D is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 10A extending through a foramen of a sacrumand anchored to the sacrum by a section of deformable material disposedin a deployed position on the lead distal to a plurality of electrodes,according to the invention;

FIG. 10E is a schematic side view of one embodiment of a distal portionof a lead with sections of deformable material disposed on the lead inundeployed positions between adjacent electrodes, according to theinvention;

FIG. 10F is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 10E with longitudinally compressed sections ofdeformable material disposed between adjacent electrodes, thelongitudinally compressed sections of deformable material radiallyexpanded into deployed positions, according to the invention;

FIG. 10G is a schematic side view of one embodiment of a distal portionof the lead shown in FIG. 10E anchored to a foramen of a sacrum by asection of longitudinally compressed and radially expanded deformablematerial disposed on the lead between two adjacent electrodes, accordingto the invention; and

FIG. 11 is a schematic overview of one embodiment of components of astimulation system, including an electronic subassembly disposed withina control module, according to the invention.

DETAILED DESCRIPTION

The present invention is directed to the area of implantable electricalstimulation systems and methods of making and using the systems. Thepresent invention is also directed to implantable electrical stimulationsystems designed for sacral nerve stimulation, the systems having leadssecured on or around sacra by one or more anchoring units coupled to theleads, as well as methods of making and using the anchoring units,leads, and electrical stimulation systems.

Suitable implantable electrical stimulation systems include, but are notlimited to, a least one lead with one or more electrodes disposed on adistal end of the lead and one or more terminals disposed on one or moreproximal ends of the lead. Leads include, for example, percutaneousleads, paddle leads, and cuff leads. Examples of electrical stimulationsystems with leads are found in, for example, U.S. Pat. Nos. 6,181,969;6,516,227; 6,609,029; 6,609,032; and 6,741,892; and U.S. patentapplication Ser. Nos. 10/353,101, 10/503,281, 11/238,240; 11/319,291;11/327,880; 11/375,638; 11/393,991; and 11/396,309, all of which areincorporated by reference.

FIG. 1 illustrates schematically one embodiment of an electricalstimulation system 100. The electrical stimulation system includes acontrol module (e.g., a stimulator or pulse generator) 102 and at leastone lead body 106 (“lead”) coupled to the control module 102. Each lead106 typically includes an array of electrodes 134. The control module102 typically includes an electronic subassembly 110 and an optionalpower source 120 disposed in a sealed housing 114. The control module102 typically includes a connector 144 (FIG. 2A, see also 222 and 250 ofFIG. 2B) into which the proximal end of the one or more leads 106 can beplugged to make an electrical connection via conductive contacts on thecontrol module 102 and terminals (e.g., 210 in FIGS. 2A and 236 of FIG.2B) on each of the one or more leads 106. In at least some embodiments,a lead is isodiametric along a longitudinal length of the lead body 106.In addition, one or more lead extensions 224 (see FIG. 2B) can bedisposed between the one or more leads 106 and the control module 102 toextend the distance between the one or more leads 106 and the controlmodule 102 of the embodiment shown in FIG. 1.

The electrical stimulation system or components of the electricalstimulation system, including one or more of the leads 106 and thecontrol module 102, are typically implanted into the body of a patient.The electrical stimulation system can be used for a variety ofapplications including, but not limited to, brain stimulation, neuralstimulation, spinal cord stimulation, muscle stimulation, and the like.

The electrodes 134 can be formed using any conductive, biocompatiblematerial. Examples of suitable materials include metals, alloys,conductive polymers, conductive carbon, and the like, as well ascombinations thereof. The number of electrodes 134 in the array ofelectrodes 134 may vary. For example, there can be two, four, six,eight, ten, twelve, fourteen, sixteen, or more electrodes 134. As willbe recognized, other numbers of electrodes 134 may also be used.

The electrodes of one or more leads 106 are typically disposed in, orseparated by, a non-conductive, biocompatible material such as, forexample, silicone, polyurethane, polyetheretherketone (“PEEK”), epoxy,and the like or combinations thereof. The leads 106 may be formed in thedesired shape by any process including, for example, molding (includinginjection molding), casting, and the like. The non-conductive materialtypically extends from the distal end of the one or more leads 106 tothe proximal end of each of the one or more leads 106.

Terminals (e.g., 210 in FIGS. 2A and 236 of FIG. 2B) are typicallydisposed at the proximal end of the one or more leads 106 of theelectrical stimulation system 100 for connection to correspondingconductive contacts (e.g., 214 in FIGS. 2A and 240 of FIG. 2B) inconnectors (e.g., 144 in FIGS. 1-2A and 222 and 250 of FIG. 2B) disposedon, for example, the control module 102 (or to conductive contacts on alead extension, an operating room cable, or an adaptor). Conductor wires(not shown) extend from the terminals (e.g., 210 in FIGS. 2A and 236 ofFIG. 2B) to the electrodes 134. Typically, one or more electrodes 134are electrically coupled to a terminal (e.g., 210 in FIGS. 2A and 236 ofFIG. 2B). In at least some embodiments, each terminal (e.g., 210 inFIGS. 2A and 236 of FIG. 2B) is only connected to one electrode 134. Theconductor wires may be embedded in the non-conductive material of thelead 106 or can be disposed in one or more lumens (not shown) extendingalong the lead 106. In some embodiments, there is an individual lumenfor each conductor wire. In other embodiments, two or more conductorwires may extend through a lumen. There may also be one or more lumens(not shown) that open at, or near, the proximal end of the lead 106, forexample, for inserting a stylet rod to facilitate placement of the lead106 within a body of a patient. Additionally, there may also be one ormore lumens (not shown) that open at, or near, the distal end of thelead 106, for example, for infusion of drugs or medication into the siteof implantation of the one or more leads 106. In at least oneembodiment, the one or more lumens may be flushed continually, or on aregular basis, with saline, epidural fluid, or the like. In at leastsome embodiments, the one or more lumens can be permanently or removablysealable at the distal end.

In at least some embodiments, leads are coupled to connectors disposedon control modules. In FIG. 2A, a lead 208 is shown configured andarranged for insertion to the control module 102. The connector 144includes a connector housing 202. The connector housing 202 defines atleast one port 204 into which a proximal end 206 of a lead 208 withterminals 210 can be inserted, as shown by directional arrow 212. Theconnector housing 202 also includes a plurality of conductive contacts214 for each port 204. When the lead 208 is inserted into the port 204,the conductive contacts 214 can be aligned with the terminals 210 on thelead 208 to electrically couple the control module 102 to the electrodes(134 of FIG. 1) disposed at a distal end of the lead 208. Examples ofconnectors in control modules are found in, for example, U.S. Pat. No.7,244,150 and U.S. patent application Ser. No. 11/532,844, which areincorporated by reference.

In FIG. 2B, a connector 222 is disposed on a lead extension 224. Theconnector 222 is shown disposed at a distal end 226 of the leadextension 224. The connector 222 includes a connector housing 228. Theconnector housing 228 defines at least one port 230 into which aproximal end 232 of a lead 234 with terminals 236 can be inserted, asshown by directional arrow 238. The connector housing 228 also includesa plurality of conductive contacts 240. When the lead 234 is insertedinto the port 230, the conductive contacts 240 disposed in the connectorhousing 228 can be aligned with the terminals 236 on the lead 234 toelectrically couple the lead extension 224 to the electrodes (134 ofFIG. 1) disposed at a distal end (not shown) of the lead 234.

In at least some embodiments, the proximal end of a lead extension issimilarly configured and arranged as a proximal end of a lead. The leadextension 224 may include a plurality of conductive wires (not shown)that electrically couple the conductive contacts 240 to a proximal end248 of the lead extension 224 that is opposite to the distal end 226. Inat least some embodiments, the conductive wires disposed in the leadextension 224 can be electrically coupled to a plurality of terminals(not shown) disposed on the proximal end 248 of the lead extension 224.In at least some embodiments, the proximal end 248 of the lead extension224 is configured and arranged for insertion into a connector disposedin another lead extension. In other embodiments, the proximal end 248 ofthe lead extension 224 is configured and arranged for insertion into aconnector disposed in a control module. As an example, in FIG. 2B theproximal end 248 of the lead extension 224 is inserted into a connector250 disposed in a control module 252.

Sometimes leads are used to stimulate nerves that extend throughforamina of bony structures, such as sacra. Sacral nerve stimulation issometimes used for treating one or more different types of ailments,including fecal incontinence, urge incontinence, interstitial cystitis,chronic pelvic pain, and urine retention. Sacral nerves can extendthrough one or more foramen of a sacrum.

Implantable electrical stimulation systems can sometimes be used fornerve stimulation and tissue stimulation, in general, including, forexample, sacral nerve stimulation. One way an electrical stimulationsystem can be implanted for sacral nerve stimulation is to position adistal end of a lead in or around one or more sacral foramina throughwhich a desired sacral nerve extends. FIG. 3 is a schematic front viewof one embodiment of a sacrum 300. The sacrum 300 includes a pluralityof foramina, such as foramen 302. Anchoring leads on or around a bonystructure, such as sacrum 300, may be difficult due to patient movementoccasionally causing anchored leads to dislodge. Previously, some leadshave been used that incorporate one or more tines disposed on a leadproximal to the plurality of electrodes. However, such tines may notprovide adequate anchoring ability and may not allow a lead to beoptimally positioned for stimulation. Additionally, when a distal end ofa lead extends through a foramen, one or more proximally-disposed tinesmay not prevent the migration of the distal end of the lead back throughthe foramen.

In at least some embodiments, anchoring units are described for use withimplantable electrical stimulation systems. In at least someembodiments, the anchoring units are configured and arranged foranchoring on or around foramina of bony structures. For example, in someembodiments, the anchoring units may be used to anchor leads to sacrafor use during sacral nerve stimulation. In some embodiments, anchoringunits are configured and arranged for anchoring a lead to the walls of aforamen of a bony structure through which the lead extends. In otherembodiments, anchoring units are configured and arranged for anchoring alead to a bony structure by extending the lead through a foramen of thebony structure and anchoring the far side of the bony structure aroundthe foramen to prevent the lead from migrating backwards through theforamen. In alternate embodiments, the anchoring units can also anchorto other features on bony structures, such as grooves, fissures, cracks,and indentations. It will also be understood that these anchoringtechniques can also be used to anchor a lead to soft tissue. Forexample, these anchoring techniques can also be used to anchor a lead tosoft tissue on either side of a foramen, or in another location that isnot in proximity to a foramen.

In some embodiments, an anchoring unit includes one or more tinesdisposed on a lead distal to a plurality of electrodes, and preferablyat a distal tip of the lead. FIG. 4A is a schematic side view of oneembodiment of a distal portion of a lead 402 with tines 404 and 406disposed in undeployed positions on the lead 402 distal to a pluralityof electrodes 408. In at least some embodiments, the tines 404 and 406are generally pressed into or against a longitudinal length of the lead402 when in an undeployed position, for example in a lead introducer, tofacilitate movement of the lead 402 without the tines 404 and 406catching on anatomical features during implantation. In someembodiments, the tines 404 and 406 overlap each other while in anundeployed position.

The tines 404 and 406 can be formed using any durable, biocompatiblematerial. Examples of suitable materials include metals, alloys,polymers, carbon, and the like, as well as combinations thereof. Anysuitable number of tines 404 and 406 may be disposed on the lead 402.For example, one, two, three, four, five, six, or more tines 404 and 406may be disposed on the lead 402. As will be recognized, other numbers oftines 404 and 406 may also be used.

In at least some embodiments, the tines 404 and 406 can be pivoted intoa deployed position. FIG. 4B is a schematic side view of one embodimentof the distal portion of the lead 402 with the tines 404 and 406disposed in deployed positions on the lead 402 distal to the pluralityof electrodes 408. The tines 404 and 406 each include a contact edge 410and a non-contact edge 412. The shapes of the tines 404 and 406 disposedon the lead 402 may vary. For example, the contact edges 410 of one ormore of the tines 404 and 406 may be straight, or curved, or convex, orconcave. Similarly, the non-contact edges 412 of one of more of thetines 404 and 406 may be straight, or curved, or convex, or concave. Inat least some embodiments, the contact edges 410 of one or more of thetines 404 and 406 may also include one or more jagged regions. Forexample, teeth may be used to increase the gripping ability of one ormore of the tines 404 and 406.

In some embodiments, the tines 404 and 406 are configured and arrangedto pivot from an undeployed position to a deployed position by adeployment mechanism (not shown) extending along at least a portion ofthe longitudinal length of a lead, such as a pullable string, wire, orstylet coupled to the tines 404 and 406 to pivot the tines 404 and 406from an undeployed position to a deployed position. In at least someembodiments, an adjustment mechanism (not shown), such as a string,wire, or stylet coupled to the tines 404 and 406 can be used to adjustthe angle or the positions of the tines 404 and 406, either together orindividually, to improve the anchoring ability of the lead 402.

In some embodiments, the tines 404 and 406 can pivot back and forthbetween deployed and undeployed positions. In other embodiments, thetines 404 and 406 can only pivot from an undeployed position to adeployed position. For example, in some embodiments the tines 404 and406 employ a spring mechanism, or the tines may be made of a resilientmaterial, which deploys when a lead introducer is retracted to pivot toa deployed position and favor maintaining the deployed position. Inwhich case, a sleeve, such as a lead introducer, can be used tofacilitate implantation of the lead 402. Once the lead 402 ispositioned, re-positioning or subsequent explantation of the lead 402may be facilitated by incorporation of the tines 404 and 406 that canpivot back and forth between deployed and undeployed positions.

FIG. 4C is schematic side view of one embodiment of a distal portion ofthe lead 402 extending through a foramen 414 of a bony structure 416.The lead 402 includes the tines 404 and 406 disposed in undeployedpositions. A lead introducer 418 is disposed over at least a portion ofthe tines 404 and 406. In at least some embodiments, the lead introducer418 can be used during implantation of the lead 402 to maintain thetines 404 and 406 in an undeployed position. In at least someembodiments, the distal portion of the lead 402 and the lead introducer418 are implanted by extending the distal portion of the lead 402 andthe lead introducer 418 through the foramen 414 of the sacrum 416 in adirection shown by directional arrow 420. In at least some embodiments,once the distal end of the lead 402 extends through the foramen 414, thelead introducer 418 can be removed from the lead 402 in a directionshown by directional arrow 422.

In at least some embodiments, once a distal end of the lead 402 ispassed through the foramen 414 and the tines 404 and 406 are pivotedfrom an undeployed position to a deployed position, the tines 404 and406 may be used to anchor the lead 402 against the bony structure 416surrounding the foramen 414. FIG. 4D is a schematic side view of oneembodiment of the distal portion of the lead 402 anchored to the bonystructure 416 by the tines 404 and 406 disposed in deployed positions onthe lead 402 distal to the plurality of electrodes 408. It will beunderstood that the tines 404 and 406 may also be used to anchor leadsin other parts of a body, including anchoring the lead 402 against bone,cartilage, and even anchoring in soft tissue. It will be understood thatthe tines 404 and 408 may be disposed on the lead 402 proximal to theplurality of electrodes 408 or between adjacent electrodes of theplurality of electrodes 408 in addition to, or instead of, distal to theplurality of electrodes 408.

In some embodiments, an anchoring unit includes one or more tinesdisposed on a lead between adjacent electrodes. FIG. 5A is a schematicside view of one embodiment of a distal portion of a lead 502. The lead502 includes a plurality of electrodes, such as electrode 504, and aplurality of tines, such as tine 506, disposed in deployed positionsbetween adjacent electrodes. In FIG. 5A, two tines are shown disposedbetween adjacent electrodes. However, any number of tines can bedisposed between adjacent electrodes. For example, there can be one,two, three, four, five, six, seven, eight, nine, ten, or more tinesdisposed between adjacent electrodes. As will be recognized, othernumbers of tines may also be disposed between adjacent electrodes. Insome embodiments, one or more rings of tines may be disposed betweenadjacent electrodes. Each ring of tines may include any number of tines.

In alternate embodiments, the tines are disposed between some adjacentelectrodes and are not disposed between other adjacent electrodes. FIG.5B is a schematic side view of the lead 502 with a tine, such as tine508, disposed between some adjacent electrodes, such as adjacentelectrodes 510 and 512. In at least some embodiments, the tines shown inFIGS. 5A and 5B can be pivoted between undeployed positions and deployedpositions and adjusted in a similar manner as the tines shown in FIGS.4A and 4B. Additionally, in some embodiments, the tines shown in FIGS.5A and 5B can overlap one another while undeployed.

FIG. 5C is a schematic side view of one embodiment of the distal portionof the lead 502 extending through a foramen 514 of a bony structure 516.The lead 502 is anchored to the walls of the foramen 514 by tinesdisposed in deployed positions between some adjacent electrodes at thedistal portion of the lead 502. In some embodiments, the tines shown inFIGS. 5A and 5B are formed from materials with suitable flexibility tofacilitate anchoring within the foramen 514 without damaging nerves andother vessels within the foramen 514. In FIG. 5C, tines 512 and 518 areshown bent against the walls of the foramen 514. It will be understoodthat the tines may be disposed on the lead 502 proximal to or distal tothe plurality electrodes in addition to, or instead of, between adjacentelectrodes. Once the lead 502 is positioned, re-positioning orsubsequent explantation of the lead 502 may be facilitated byincorporation of the tines that can pivot back and forth betweendeployed and undeployed positions.

In some embodiments, an anchoring unit disposed on a lead includes oneor more tines that are arranged spirally around the circumference of alead when in an undeployed position. FIG. 6A is a schematic axialcross-sectional view of one embodiment of a lead 602 that includes aplurality of tines 604, such as tines 606-611, disposed spirally inundeployed positions in an annular groove 612 disposed on the lead 602.The tines 604 can have any suitable shape for anchoring. For example,the tines 604 may have shapes that are rod-shaped, plate-shaped,wing-shaped, branch-shaped, and the like. As will be recognized, othershapes may also be used. Additionally, the cross-sectional shapes of thetines 604 may have any suitable form. For example, the tines 604 mayhave cross-sectional shapes that are round, triangular, rectangular,semi-circular, and the like. As will be recognized, othercross-sectional shapes may also be used. In some embodiments, the tineshave at least one sharp edge configured and arranged for anchoring tobone. In other embodiments, the tines have at least one blunt endconfigured and arranged for anchoring to soft tissue or to amelioratedamage to tissue and vessels when anchoring to bone.

In at least some embodiments, the tines 604 are transitioned to deployedpositions by twisting or rotating a first portion of the lead 602 inrelation to a second portion of the lead 602. For example, in at leastsome embodiments, twisting or rotating a portion of the lead 602 in aclockwise direction, as shown by directional arrow 614, causes the tines604 to advance from the annular groove 612. In at least someembodiments, the rate of deployment of the tines 604 may be controlledby the twisting or rotation rate. In at least some embodiments, theamount of twisting or rotating of the first portion of the lead 602 inrelation to the second portion of the lead 602 controls the amount ofthe tines 604 advanced from the annular groove 612. In at least someembodiments, the amount of twisting or rotating of the first portion ofthe lead 602 in relation to the second portion of the lead 602 controlsthe angle the times 604 form with the lead 602 in addition to, orinstead of, the amount of the tines 604 advanced from the annular groove612.

FIG. 6B is a schematic axial cross-sectional view of one embodiment ofthe tines 604 in partially-deployed positions. In at least someembodiments, counterclockwise twisting or rotating, as shown bydirectional arrow 616, of the first portion of the lead 602 in relationto the second portion of the lead 602, causes the tines 604 to retracttowards undeployed positions, as shown in FIG. 6A. In other embodiments,deploying the tines 604 is substantially permanent and the tines 604 arenot returned to their undeployed position by twisting or rotating in theopposite direction. For example, the deployment of the tines 604 mayrelease tine stops, or move the tines 604 past tine stops, therebypreventing return of the tines to an undeployed position.

In at least some embodiments, additional clockwise twisting or rotating614 of the first portion of the lead 602 in relation to the secondportion of the lead 602 further advances the tines 604 from the annulargroove 612. FIG. 6C is a schematic axial cross-sectional view of oneembodiment of the tines 604 in fully-deployed positions on the lead 602.In at least some embodiments, a mechanism can be employed to retain thetines 604 in fully-deployed positions. In some embodiments, theretention mechanism for retaining the tines 604 in fully-deployedpositions can also be used to retract the tines 604. Once the tines 604are in either partially deployed positions or fully-deployed positions,the lead 602 can be anchored to a bony structure or to soft tissue, suchas soft tissue in proximity to a bony structure. For example, the lead602 can be anchored to a foramen or to a sacrum on the opposite side ofthe foramen from the proximal end (not shown) of the lead 602, as shownin FIGS. 5D and 4C, respectively.

FIG. 6D is a schematic side view of one embodiment of the distal portionof the lead 602 extending through a foramen 618 of a sacrum 620 andanchored to the walls of the foramen 618 by the tines 604 infully-deployed positions at the distal portion of the lead 602. In otherembodiments, the tines 604 are disposed in other locations along thelongitudinal length of the lead 602. For example, the tines 604 may bedisposed distal to the electrodes, or disposed proximal to theelectrodes. In at least some embodiments, more than one plurality oftines 604 is disposed on the lead 602. For example, multiple rings oftines 604 may be positioned along the length of the lead 602.

In at least some embodiments, the tines 604 are disposed in an outerring of the lead 602 with cutouts for the tines 604. FIG. 6E is aschematic perspective view of one embodiment of a portion of the lead602 including an outer ring 622 with cutouts, such as cutout 624. In atleast some embodiments, the cutouts may be designed such that when auser rotates the outer ring 622 in a first direction, one or more tines604 advance from each cutout (as shown in FIG. 6F). In at least someembodiments, rotation of the outer ring 622 in a second direction causesthe one or more tines 604 to retract. In at least some embodiments, anouter surface 626 of the outer ring 622 is isodiametric with an outersurface of the lead 602. In at least some embodiments, the tines 604 aredisposed in an inner ring 628 when in an undeployed position. Inalternate embodiments, the tines 604 may be advanced or retracted byrotating the inner ring 628 instead of, or in addition to, rotating theouter ring 622.

In some embodiments, an anchoring unit disposed on a lead includes oneor more radially expanding springs. FIG. 7A is a schematic axialcross-sectional view of one embodiment of a lead 702 that includes aspring 704 in an undeployed position disposed in an annular groove 706on the lead 702. In at least some embodiments, the diameter of thespring 704 while in an undeployed position is no greater than thediameter of the lead 702. FIG. 7B is a schematic axial cross-sectionalview of one embodiment of the spring 704 disposed in a deployed positionin the annular groove 706 on the lead 702. In at least some embodiments,the diameter of the spring 704 while in a deployed position is greaterthan the diameter of a lead. In at least some embodiments, the diameterof the spring 704 in a deployed position may be greater than thediameter of the foramen.

In some embodiments, the spring 704 can be implanted using a removablelead introducer disposed over at least a portion of the spring 704 tokeep the spring 704 in an undeployed position during positioning of thelead 702 in a similar manner as the lead 402 shown in FIG. 4C. Once thelead 702 is positioned, the introducer may be removed, allowing thespring 704 to use stored potential energy to transfer to a deployedposition and anchor the lead 702. In other embodiments, the spring 704is configured and arranged to remain in an undeployed position by amechanism that does not include a lead introducer disposed over thespring 704. In some embodiments, the spring 704 may be placed in adeployed position by twisting or rotating a first portion of the lead702 in relation to a second portion of the lead 702 in a manner similarto the technique described above for the spirally-arranged tines 604.For example, in at least some embodiments, twisting or rotating aportion of the lead 702 in a clockwise direction causes the spring 704to advance from the annular groove 706 and into a deployed position.

In at least some embodiments, the rate of deployment of the spring 704may be controlled by the twisting or rotation rate. In at least someembodiments, the amount of twisting or rotating of the first portion ofthe lead 702 in relation to the second portion of the lead 702 controlsthe amount of the spring 704 advanced from the annular groove 706. In atleast some embodiments, counterclockwise twisting or rotating of thefirst portion of the lead in relation to the second portion of the leadcauses the spring 704 to retract towards an undeployed position, asshown in FIG. 7A. In at least some embodiments, the lead 702 includes arelease switch or button for deploying at least a portion of the spring704 at a predetermined rate using potential energy stored in the spring704.

In at least some embodiments, the spring 704 can be used to anchor thelead 702 to a bony structure or to soft tissue. FIG. 7C is a schematicside view of one embodiment of the distal portion of the lead 702extending through a foramen 708 of a bony structure 710 and anchoredagainst the bony structure 710 by the spring 704 disposed in a deployedposition on the distal portion of the lead 702. In other embodiments,the spring 704 is disposed in other locations along the longitudinallength of the lead 702. For example, the spring 704 may be disposedbetween two adjacent electrodes, or disposed along the longitudinallength of the spring 704 proximal to the electrodes. In at least someembodiments, more than one spring 704 is disposed on the lead 702.

As shown in FIG. 7C, the lead 702 extends through the foramen 708defined in the sacrum 710 and the spring 704 is in a deployed positionon an opposite side of the sacrum 710 from a proximal end (not shown) ofthe lead 702. The spring 704 has a diameter, shown in FIG. 7C as atwo-headed dotted arrow 712, and the foramen 708 has a diameter, shownin FIG. 7C as a two-headed dotted arrow 714. The diameter 712 of thespring 704 is greater in length than the diameter 714 of the foramen708. Thus, the spring 704 in a deployed position prevents the lead 702from migrating back through the foramen 708. In alternate embodiments,the spring 704 is placed in a deployed position within the foramen 708to anchor the lead 702 to the foramen 708. In yet other embodiments, thespring 704 is placed in a deployed position to anchor the lead 702against cartilage or soft tissue. In at least some embodiments, thediameter of the spring 704 in a deployed position is greater than thelead 702, but less than the foramen 708. It will be understood thatprevention of migration of the lead 702 may also occur when the diameterof the spring 704 in a deployed position is greater than the lead 702,but less than the diameter of the foramen 708. Note that, in somecircumstances it may be undesirable for the diameter of the spring 704in a deployed position to have a diameter that is less than the diameterof the foramen 708 so as to reduce the risk of damaging soft tissueextending through the foramen 708.

In at least some embodiments, the spring 704 is disposed in an outerring of the lead 702 with a cutout for the spring 704. FIG. 7D is aschematic perspective view of one embodiment of a portion of the lead702 including an outer ring 716 with a cutout 718. In at least someembodiments, the cutout 718 may be designed such that when a userrotates the outer ring 716 in a first direction, the spring 704 advancesfrom the cutout 718 (as shown in FIG. 7E). In at least some embodiments,rotation of the outer ring 716 in a second direction causes the spring704 to retract. In at least some embodiments, an outer surface 720 ofthe outer ring 716 is isodiametric with an outer surface of the lead702. In at least some embodiments, the spring 704 is disposed in aninner ring 722 when in an undeployed position. In alternate embodiments,the spring 704 may be advanced or retracted by rotating the inner ring722 instead of, or in addition to, rotating the outer ring 716.

In some embodiments, an anchoring unit disposed on a lead includes oneor more expandable stents disposed on a lead. FIG. 8A is a schematicside view of one embodiment of a distal portion of a lead 802 thatincludes an expandable stent 804 disposed in an undeployed position overa portion of the lead 802 distal to a plurality of electrodes 806. In atleast some embodiments, the lead 802 can be positioned while the stent804 is in an undeployed position. Once the lead 802 is positioned, thestent 804 can be transitioned to a deployed position by expanding thestent 804. In some embodiments, the stent 804 can be implanted using aremovable lead introducer disposed over at least a portion of the stent804 to maintain the stent 804 in an undeployed position duringpositioning of the lead 702 in a similar manner as the lead 402 shown inFIG. 4C. In alternate embodiments, the stent 804 may also becontractible, so that the stent 804 can transition from a deployedposition to an undeployed position.

FIG. 8B is a schematic side view of one embodiment of a distal portionof the lead 802. The lead 802 includes the stent 804 disposed in adeployed position over the distal portion of the lead 802. In someembodiments, the stent 804 is positioned between adjacent electrodes806. In other embodiment, the stent 804 is positioned along a portion ofthe longitudinal length of the lead 802 proximal to the electrodes 806.In at least some embodiments, more than one stent 804 is disposed on thelead 802.

In at least some embodiments, the stent 804 remains coupled to the lead802 when the stent 804 is in a deployed position. In at least oneembodiment, the stent 804 remains coupled to the lead 802 by anattachment mechanism coupled to the stent 804 along an interior surfaceof the stent 804. In other embodiments, one or more of the ends of thestent 804 remain fixed to the lead 802 when the stent 804 is in adeployed position. FIG. 8C is a schematic side view of anotherembodiment of a distal portion of the lead 802 including the expandablestent 804 disposed in a deployed position over a portion of the lead802. The stent 804 includes a distal end 808 and a proximal end 810 thatare fixed to the lead 802.

In at least some embodiments, the stent 804 can be used to anchor thelead 802 to a bony structure or to soft tissue. FIG. 8D is a schematicside view of one embodiment of the distal portion of the lead 802extending through a foramen 812 of a bony structure 814 and anchored tothe bony structure 814 by the stent 804 disposed in a deployed positionon the distal portion of the lead 802. As shown in FIG. 8D, the lead 802extends through a foramen 812 of the bony structure 814 and the stent804 is in a deployed position on an opposite side of the sacrum 814 froma proximal end (not shown) of the lead 802. The stent 804 has adiameter, shown in FIG. 8D as a two-headed dotted arrow 816, and theforamen 812 has a diameter, shown in FIG. 8D as a two-headed dottedarrow 818. The diameter 916 of the stent 904 is greater in length thanthe diameter 818 of the foramen 812. Thus, the stent 804 prevents thelead 802 from migrating back through the foramen 812. In alternateembodiments, the stent 804 is placed in a deployed position within theforamen 812 to anchor the lead 802 to the foramen 812. In yet otherembodiments, the stent 804 is placed in a deployed position to anchorthe lead 802 against cartilage or soft tissue. In at least someembodiments, the diameter of the stent 804 in a deployed position isgreater than the lead 802, but less than the foramen 812. It will beunderstood that prevention of migration of the lead 802 may also occurwhen the diameter of the stent 804 in a deployed position is greaterthan the lead 802, but less than the diameter of the foramen 812. Notethat, in some circumstances it may be undesirable for the diameter ofthe stent 804 in a deployed position to have a diameter that is lessthan the diameter of the foramen 812 so as to reduce the risk ofdamaging soft tissue extending through the foramen 812.

In some embodiments, an anchoring unit disposed on a lead includes a tipthat may expand. FIG. 9A is a schematic side view of one embodiment of adistal portion of a lead 902 that includes a tip 904 that may expanddisposed in an undeployed position on the lead 902 distal to a pluralityof electrodes 906. In at least some embodiments, the lead 902 can bepositioned while the tip 904 is in an undeployed position. Once the lead902 is positioned, the tip 904 can be transitioned to a deployedposition by expanding the tip 904. In at least some embodiments, the tip904 is permanently or removably coupled to a distal tip of the lead 902.In at least some embodiments, a stylet disposed in a lumen defined inthe lead 902 may be used to push against the tip 904, causing the tip904 to expand.

FIG. 9B is a schematic side view of one embodiment of a distal portionof the lead 902 including a tip 904 disposed in a deployed position onthe lead 902 distal to the plurality of electrodes 906. In at least someembodiments, the tip 904 is configured and arranged to maintain adeployed position and may be implanted using a lead introducer disposedover the tip 904 in a manner similar to the lead 402 shown in FIG. 4C.In alternate embodiments, the tip 904 may also be contractible, so thatthe tip 904 can transition from a deployed position to an undeployedposition.

In at least some embodiments, the tip 904 can be used to anchor the lead902 to a bony structure. FIG. 9C is a schematic side view of oneembodiment of the distal portion of the lead 902 extending through aforamen 908 of a bony structure 910 and anchored to the bony structure910 by the tip 904 disposed in a deployed position on the distal portionof the lead 902. As shown in FIG. 9C, the lead 902 extends through theforamen 908 of the bony structure 908 and the tip 904 is in a deployedposition on an opposite side of the foramen 908 from a proximal end (notshown) of the lead 902. The tip 904 has a diameter, shown in FIG. 9C asa two-headed dotted arrow 912, and the foramen 908 has a diameter, shownin FIG. 9C as a two-headed dotted arrow 914. The diameter 912 of the tip904 is greater in length than the diameter 914 of the foramen 908. Thus,the sphere 904 prevents the lead 902 from migrating back through theforamen 908. In alternate embodiments, the tip 904 is placed in adeployed position within the foramen 908 to anchor the lead 902 to theforamen 908. In yet other embodiments, the tip 904 is placed in adeployed position to anchor the lead 902 against cartilage or softtissue. In at least some embodiments, the diameter of the tip 904 in adeployed position is greater than the lead 902, but less than theforamen 908. It will be understood that prevention of migration of thelead 902 may also occur when the diameter of the tip 904 in a deployedposition is greater than the lead 902, but less than the diameter of theforamen 908. Note that, in some circumstances it may be undesirable forthe diameter of the tip 904 in a deployed position to have a diameterthat is less than the diameter of the foramen 908 so as to reduce therisk of damaging soft tissue extending through the foramen 908.

In some embodiments, an anchoring unit disposed on a lead includes oneor more sections of deformable material disposed on a lead. FIG. 10A isa schematic side view of one embodiment of a distal portion of a lead1002 that includes a section of deformable material 1004 disposed in anundeployed position on the lead 1004 distal to a plurality of electrodes1006. The section of deformable material 1004 may be formed in a numberof different shapes. For example, the deformable material 1004 may becylindrical, O-ring-shaped, gasket-shaped, annulus-shaped, and the like.The deformable material 1004 may be formed by, a pliable, reformable,biocompatible material including, for example, rubber, and the like. Inat least some embodiments, the deformable material 1004 is sandwichedbetween materials less deformable than the deformable material 1004.

In at least some embodiments, when the deformable material 1004 islongitudinally compressed, the deformable material 1004 expandsradially. For example, when a portion of the lead 1002 distal to thedeformable material is moved relative to the remaining portion of thelead 1002 in a direction shown by directional arrow 1008, or the portionof the lead proximal to the deformable material is moved relative to theremaining portion of the lead 1002 in a direction shown by directionalarrow 1010, the deformable material may expand in one or more radialdirections approximately orthogonal to a longitudinal length of the lead1002, such as the directions shown by directional arrows 1012 and 1014.

In at least some embodiments, the lead 1002 may include a movable innersection that may be used to compresses the deformable material 1004between a distal tip and stationary outer section. FIG. 10B is aschematic longitudinal cross-sectional view of one embodiment of thedistal portion of the lead 1002. The lead 1002 includes a movable innersection 1016, a stationary outer section 1018, a distal tip 1020, andthe deformable material 1004. In at least some embodiments, the distaltip 1020 is coupled to distal end of the movable inner section 1016. Inat least some embodiments, the inner section 1004 is a stylet. When theinner section 1016 is moved in a direction as shown by directional arrow1008, the deformable material 1004 may be compressed between the distaltip 1020 and the stationary outer section 1018, causing the deformablematerial 1004 to expand in one or more radial directions approximatelyorthogonal to a longitudinal length of the lead 1002, such as thedirections shown by directional arrows 1012 and 1014. In at least someembodiments, one or more stops may be used to removably or permanentlymaintain the deformable material 1004 in a compressed (deployed)position.

FIG. 10C is a schematic side view of one embodiment of a distal portionof the lead 1002 longitudinally compressed, thereby causing thedeformable material 1004 to radially expand. In at least someembodiments, the portion 1022 of the lead 1002 distal to the deformablematerial 1004 is moved proximally relative to the remaining portion ofthe lead 1002 by screwing or pulling the portion 1022 of the lead 1002distal to the deformable material 1004 relative to the remainingportions of the lead 1002. In at least some embodiments, the portion1024 of the lead 1002 proximal to the deformable material 1004 is moveddistally relative to the remaining portion of the lead 1002 by screwingor pulling the portion 1024 of the lead 1002 proximal to the deformablematerial 1004 relative to the remaining portions of the lead 1002. In atleast some embodiments, both the portion 1022 of the lead 1002 distal tothe deformable region 1004 and the portion 1022 of the lead 1002proximal to the deformable region 1004 are pulled or screwedlongitudinally inward to longitudinally compress the deformable region1004.

In at least some embodiments, the section of deformable material 1004disposed at the distal end of the lead 1002 can be used to anchor thelead 1002 to a bony structure or to soft tissue. FIG. 10D is a schematicside view of one embodiment of the distal portion of the lead 1002extending through a foramen 1026 of a bony structure 1028 and anchoredto the bony structure 1028 by the deformable material 1004 disposed in adeployed position on the distal portion of the lead 1002. As shown inFIG. 10D, the lead 1002 extends through the foramen 1026 of the bonystructure 1028 and the section of deformable material 1004 is in adeployed position on an opposite side of the bony structure 1028 from aproximal end (not shown) of the lead 1002. The deformable material 1004has a diameter, shown in FIG. 10D as a two-headed dotted arrow 1030, andthe foramen 1026 has a diameter, shown in FIG. 10D as a two-headeddotted arrow 1032. The diameter 1030 of the deformable material 1004 isgreater in length than the diameter 1032 of the foramen 1026. Thus, thedeformable material 1004 prevents the lead 1002 from migrating backthrough the foramen 1026. In alternate embodiments, the deformablematerial 1004 is placed in a deployed position within the foramen 1026to anchor the lead 1004 to the foramen 1026. In yet other embodiments,the deformable material 1004 is placed in a deployed position to anchorthe lead 1002 against cartilage or soft tissue. In at least someembodiments, the diameter of the deformable material 1004 in a deployedposition is greater than the lead 1002, but less than the foramen 1026.It will be understood that prevention of migration of the lead 1002 mayalso occur when the diameter of the deformable material 1004 in adeployed position is greater than the lead 1002, but less than thediameter of the foramen 1026. Note that, in some circumstances it may beundesirable for the diameter of the deformable material 1004 to have adiameter in a deployed position that is less than the diameter of theforamen 1026 so as to reduce the risk of damaging soft tissue extendingthrough the foramen 1026.

In at least some embodiments, more than one section of deformablematerial 1004 can be disposed on the lead 1002 distal to the electrodes1006. In at least some embodiments, one or more sections of deformablematerial 1004 can be disposed along other portions of the lead 1002. Forexample, the one or more sections of deformable material 1004 may bedisposed between adjacent electrodes 1006, or on a portion of the lead1002 proximal to the electrodes 1006. FIG. 10E is a schematic side viewof one embodiment of a distal portion of the lead 1002. The lead 1002includes sections of deformable material 1034-1036 disposed on the lead1002 in undeployed positions between electrodes 1006. In someembodiments, a single section of deformable material 1034-1036 isdisposed between two adjacent electrodes 1006. In other embodiments,more than one section of deformable material 1034-1036 is disposedbetween electrodes 1006.

In at least some embodiments, the deformable material 1034-1036 can belongitudinally compressed, thereby causing the deformable material1034-1036 to radially expand in a manner similar to the method oflongitudinally compressing the deformable material 1004 discussed above,with reference to FIGS. 10A and 10B. FIG. 10F is a schematic side viewof one embodiment of a distal portion of the lead 1002 longitudinallycompressing sections of deformable material 1034-1036 to radially expandthe sections of deformable material 1034-1036 into deployed positions.

In at least some embodiments, one or more of the sections of deformablematerial 1034-1036 disposed between electrodes on the lead 1002 can beused to anchor the lead 1002 to a bony structure or soft tissue. FIG.10G is a schematic side view of one embodiment of the lead 1002extending through a foramen 1038 of a bony structure 1040 and anchoredto the walls of the foramen 1038 by the section of deformable material1036 disposed in a deployed position on the distal portion of the lead1002. In some embodiments, one or more of the sections of deformablematerial 1034-1036 are in a deployable position. In alternateembodiments, each of the sections of deformable material 1034-1036 is ina deployed position. In other embodiments, one or more of the sectionsof deformable material 1034-1036 disposed between the electrodes isplaced in a deployed position on the opposite side of the bony structure1040 from a proximal end (not shown) of the lead 1002, in a similarmanner as shown in FIG. 10D. In yet other embodiments, one or more ofthe sections of the deformable material 1034-1036 is placed in adeployed position to anchor the lead 1002 against cartilage or softtissue. In at least some embodiments, the diameter of one or moresections of deformable material 1034-1036 in deployed positions isgreater than the lead 1002, but less than the foramen 1038. It will beunderstood that prevention of migration of the lead 1002 may also occurwhen the diameter of one or more sections of deformable material1034-1036 in deployed positions is greater than the lead 1002, but lessthan the diameter of the foramen 1038. Note that, in some circumstancesit may be undesirable for the diameter of one or more sections of thedeformable material 1034-1036 in deployed positions to have diametersthat are less than the diameter of the foramen 1038 so as to reduce therisk of damaging soft tissue extending through the foramen 1038.

In at least some embodiments, a plurality of anchoring units can be usedto anchor a lead. In at least some embodiments, a plurality of differenttypes of anchoring units disposed on one or more different locations onthe lead may be used to anchor a lead. For example, a lead may includeboth one or more tines and one or more sections of deformable materials.In another example, a lead may include one or tines, an expandable tip,and a spring. In at least some embodiments, an anchoring unit is atleast partially formed from, or coated by, one or more porous materialsconfigured and arranged to facilitate integration of the anchoring unitto at least one bony structure, such as a sacrum.

FIG. 11 is a schematic overview of one embodiment of components of anelectrical stimulation system 1100 including an electronic subassembly1110 disposed within a control module. It will be understood that theelectrical stimulation system can include more, fewer, or differentcomponents and can have a variety of different configurations includingthose configurations disclosed in the stimulator references citedherein.

Some of the components (for example, power source 1112, antenna 1118,receiver 1102, and processor 1104) of the electrical stimulation systemcan be positioned on one or more circuit boards or similar carrierswithin a sealed housing of an implantable pulse generator, if desired.Any power source 1112 can be used including, for example, a battery suchas a primary battery or a rechargeable battery. Examples of other powersources include super capacitors, nuclear or atomic batteries,mechanical resonators, infrared collectors, thermally-powered energysources, flexural powered energy sources, bioenergy power sources, fuelcells, bioelectric cells, osmotic pressure pumps, and the like includingthe power sources described in U.S. Patent Application Publication No.2004/0059392, incorporated herein by reference.

As another alternative, power can be supplied by an external powersource through inductive coupling via the optional antenna 1118 or asecondary antenna. The external power source can be in a device that ismounted on the skin of the user or in a unit that is provided near theuser on a permanent or periodic basis.

If the power source 1112 is a rechargeable battery, the battery may berecharged using the optional antenna 1118, if desired. Power can beprovided to the battery for recharging by inductively coupling thebattery through the antenna to a recharging unit 1116 external to theuser. Examples of such arrangements can be found in the referencesidentified above.

In one embodiment, electrical current is emitted by the electrodes 134on the paddle or lead body to stimulate nerve fibers, muscle fibers, orother body tissues near the electrical stimulation system. A processor1104 is generally included to control the timing and electricalcharacteristics of the electrical stimulation system. For example, theprocessor 1104 can, if desired, control one or more of the timing,frequency, strength, duration, and waveform of the pulses. In addition,the processor 1104 can select which electrodes can be used to providestimulation, if desired. In some embodiments, the processor 1104 mayselect which electrode(s) are cathodes and which electrode(s) areanodes. In some embodiments, the processor 1104 may be used to identifywhich electrodes provide the most useful stimulation of the desiredtissue.

Any processor can be used and can be as simple as an electronic devicethat, for example, produces pulses at a regular interval or theprocessor can be capable of receiving and interpreting instructions froman external programming unit 1108 that, for example, allows modificationof pulse characteristics. In the illustrated embodiment, the processor1104 is coupled to a receiver 1102 which, in turn, is coupled to theoptional antenna 1118. This allows the processor 1104 to receiveinstructions from an external source to, for example, direct the pulsecharacteristics and the selection of electrodes, if desired.

In one embodiment, the antenna 1118 is capable of receiving signals(e.g., RF signals) from an external telemetry unit 1106 which isprogrammed by a programming unit 1108. The programming unit 1108 can beexternal to, or part of, the telemetry unit 1106. The telemetry unit1106 can be a device that is worn on the skin of the user or can becarried by the user and can have a form similar to a pager, cellularphone, or remote control, if desired. As another alternative, thetelemetry unit 1106 may not be worn or carried by the user but may onlybe available at a home station or at a clinician's office. Theprogramming unit 1108 can be any unit that can provide information tothe telemetry unit 1106 for transmission to the electrical stimulationsystem 1100. The programming unit 1108 can be part of the telemetry unit1106 or can provide signals or information to the telemetry unit 1106via a wireless or wired connection. One example of a suitableprogramming unit is a computer operated by the user or clinician to sendsignals to the telemetry unit 1106.

The signals sent to the processor 1104 via the antenna 1118 and receiver1102 can be used to modify or otherwise direct the operation of theelectrical stimulation system. For example, the signals may be used tomodify the pulses of the electrical stimulation system such as modifyingone or more of pulse duration, pulse frequency, pulse waveform, andpulse strength. The signals may also direct the electrical stimulationsystem 1100 to cease operation, to start operation, to start chargingthe battery, or to stop charging the battery. In other embodiments, thestimulation system does not include an antenna 1118 or receiver 1102 andthe processor 1104 operates as programmed.

Optionally, the electrical stimulation system 1100 may include atransmitter (not shown) coupled to the processor 1104 and the antenna1118 for transmitting signals back to the telemetry unit 1106 or anotherunit capable of receiving the signals. For example, the electricalstimulation system 1100 may transmit signals indicating whether theelectrical stimulation system 1100 is operating properly or not orindicating when the battery needs to be charged or the level of chargeremaining in the battery. The processor 1104 may also be capable oftransmitting information about the pulse characteristics so that a useror clinician can determine or verify the characteristics.

The above specification, examples and data provide a description of themanufacture and use of the composition of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention also resides in theclaims hereinafter appended.

1. A nerve stimulation lead comprising: a lead body with a distal end, aproximal end, and a longitudinal length; a plurality of electrodesdisposed at the distal end; a plurality of terminals disposed at theproximal end; a plurality of conductive wires electrically coupling theplurality of electrodes electrically to the plurality of terminals; anda plurality of anchoring units configured and arranged for anchoring thenerve stimulation lead against a bony structure or against soft tissueabutting a bony structure, each of the plurality of anchoring units isconfigured and arranged to transition between an undeployed position anda deployed position, the undeployed position facilitating positioning ofthe nerve stimulation lead and the deployed position facilitatinganchoring of the nerve stimulation lead, wherein, in the undeployedposition, each anchoring unit is disposed within the lead body and, inthe deployed position, each anchoring units extends from the lead body.2. The nerve stimulation lead of claim 1, wherein the plurality ofanchoring units comprises at least two tines disposed on the nervestimulation lead.
 3. The nerve stimulation lead of claim 1, wherein theplurality of anchoring units are configured and arranged to transitionfrom the undeployed position to the deployed position by twisting atleast a portion of the nerve stimulation lead.
 4. The nerve stimulationlead of claim 3, wherein the plurality of anchoring units are configuredand arranged to return to the undeployed position when at least aportion of the lead is twisted in a direction opposite that used todeploy the at least one anchoring unit.
 5. The nerve stimulation lead ofclaim 1, wherein the plurality of anchoring units comprise a firstanchoring unit and a second anchoring unit and the first and secondanchoring units are disposed on the stimulation lead between differentpairs of the plurality of electrodes.
 6. The nerve stimulation lead ofclaim 1, wherein the plurality of anchoring units comprise a pluralityof tines arranged in a plurality of spaced-apart rings.
 7. An electricalstimulating system comprising: the nerve stimulation lead of claim 1;and a control module configured and arranged to electrically couple tothe proximal end of the nerve stimulation lead, the control modulecomprising a housing, and an electronic subassembly disposed in thehousing; and a connector for receiving the nerve stimulation lead, theconnector having a proximal end and a distal end, the connectorconfigured and arranged to receive the nerve stimulation lead, theconnector comprising a connector housing defining a port at the distalend of the connector, the port configured and arranged for receiving theproximal end of the nerve stimulation lead, and a plurality of connectorcontacts disposed in the connector housing, the connector contactsconfigured and arranged to couple to at least one of the plurality ofterminals disposed on the proximal end of the lead body.
 8. A method ofstimulating tissue, the method comprising: implanting a nervestimulation lead near tissue to be stimulated, the nerve stimulationlead comprising a plurality of electrodes disposed at a distal end ofthe nerve stimulation lead; a plurality of terminals disposed at aproximal end of the nerve stimulation lead; a plurality of conductivewires electrically coupling the plurality of electrodes electrically tothe plurality of terminals; and at least one anchoring unit disposed onthe nerve stimulation lead, wherein during implantation the at least oneanchoring unit is in an undeployed position; deploying the at least oneanchoring unit by twisting at least a portion of the nerve stimulationlead; anchoring the nerve stimulation lead against a bony structure oragainst soft tissue abutting a bony structure using the at least oneanchoring unit that has been deployed; and stimulating the tissue usinga current provided through at least one of the plurality of electrodes.9. The method of claim 8, wherein anchoring the nerve stimulation leadcomprises anchoring the nerve stimulation lead to a wall of a foramen ofthe bony structure or to soft tissue extending along the wall of theforamen.
 10. The method of claim 8, wherein anchoring the nervestimulation lead comprises anchoring the nerve stimulation lead inproximity to a foramen of the bony structure through which the distalend of the nerve stimulation lead at least partially extends.
 11. Themethod of claim 8, wherein anchoring the nerve stimulation leadcomprises anchoring the nerve stimulation lead against a first side ofthe bony structure in proximity to a foramen through which the distalend of the nerve stimulation lead at least partially extends, the firstside of the bony structure being opposite to a side of the bonystructure through which the distal end of the nerve stimulation leadentered the foramen.
 12. The method of claim 8, wherein the at least oneanchoring unit comprises at least two deployable tines disposed on thenerve stimulation lead.
 13. The method of claim 12, wherein each tinehas an undeployed position in which it lies against the lead and adeployed position in which it projects outward from the lead.
 14. Themethod of claim 13, further comprising returning the at least twodeployable tines to the undeployed position by twisting at least aportion of the lead in a direction opposite that used in deploying theat least two deployable tines.
 15. The method of claim 13, wherein, oncedeployed, the at least two deployable tines are configured and arrangedto remain in the deployed position even if at least a portion of thelead is rotated in a direction opposite that used in deploying the atleast two deployable tines.
 16. The method of claim 8, wherein that atleast one anchoring unit comprises a spring having a deployed positionand an undeployed position, the spring having higher potential energy inthe undeployed position than in the deployed position.
 17. The method ofclaim 8, wherein deploying the at least one anchoring unit comprisesdeploying the at least one anchoring unit from at least one annulargroove formed in the nerve stimulation lead by twisting at least theportion of the nerve stimulation lead.
 18. A method of stimulatingtissue, the method comprising: implanting a nerve stimulation lead neartissue to be stimulated, the nerve stimulation lead comprising aplurality of electrodes disposed at a distal end of the nervestimulation lead; a plurality of terminals disposed at a proximal end ofthe nerve stimulation lead; a plurality of conductive wires electricallycoupling the plurality of electrodes electrically to the plurality ofterminals; and at least one anchoring unit disposed on the nervestimulation lead, wherein at least one of the anchoring units comprisesan expandable tip disposed on the nerve stimulation lead distal to theplurality of electrodes, wherein during implantation the expandable tipis in an undeployed position; deploying the expandable tip by pushingagainst the undeployed expandable tip using a stylet disposed within thenerve stimulation lead; anchoring the nerve stimulation lead against abony structure or against soft tissue abutting a bony structure usingthe deployed expandable tip; and stimulating the tissue using a currentprovided through at least one of the plurality of electrodes.